Then a thought struck me: If you are worried about something (global warming, peak oil, the end of the world as we know it, whatever - pro or denier, counting on your POV) and you hang around sites filled with like-minded people, how do you keep yourself and your group from reinforcing that shared viewpoint to the point where you go beyond the real data, where it starts to function as belief instead of knowledge?
This may be a pretty hard-wired human tendency. We tend to hang with people who share a similar POV, and we keep our group identity by reinforcing each other through repetitions of our core beliefs, which may or may not be fact based; and often we label those who don't share our beliefs with nasty labels - I've seen it in fandom groups, as people orient around favored pairings or canon v. non-canon or slash v. non-slash, computer operating systems (Mac vs. PC always starts religious wars!), various niches in science (start looking at some of the hot wars in archaeology for a start, but there are other areas where it went or is still going hot). I won't even talk about high school groups, religion or politics.
How do we avoid it? This zero-sum, Us vs. Them, self-reinforcing polarization has caused us a lot of grief as a species. But it gets even worse when one has to make rational decisions about tricky scientific and economic issues. How do we keep belief out of the reality of what the data says? Is it even possible?